Gun launched, terminal guided projectile



Jan. 8, 1963 s. ROSS 3,072,055

GUN LAUNCHED, TERMINAL GUIDED PROJECTILE Filed Aug. :5, 1959 FIG.2.

FlG.l.

FIG. 3.

JNVENTOR. SIDNEY ROSS ATTORNEYS:

United States atent Gfifice 3,672,055 Patented Jan. 8, 1963 3,072,055GUN LAUNCEE TERMINAL GUIDED PROJECTILE Sidney Ross, 1212 Gilham St.,Philadelphia, Pa. Filed Aug. 3, 1959, Ser. No. 831,443 2 Claims. (Cl.102-50) (Granted under Title 35, US. Code (1952), sec. 266) Theinvention described herein may be manufactured and used by or for theGovernment for governmental purposes without the payment to me of anyroyalty thereon.

This invention relates to projectiles which have within themselves meansfor recognizing and correcting an error in their trajectory with respectto a target, and has for its principal object the provision of acompensated trajectory projectile which avoids the complexity heretoforecharacteristic of such projectiles.

Various types of compensated trajectory projectiles have been proposed.These prior art projectiles have usually involved the use of a pluralityof charges and complicated systems of one kind or another forcontrolling the firing of these charges. Thus United States Patent2,415,348 of J. E. Haigney discloses a projectile including a pluralityof charges, the firing of which is controlled by a relay systemconnected between them and a pair of photoelectric cells. A priorsuggestion has contemplated charges fired under control of a gyroscope.In each case, (1) the charges are fired in response to the operation ofmoving mechanisms, and (2) a plurality of charges are utilized to applythrusts whereby the trajectory of the projectile is corrected.

The present invention is distinguished by the fact that it involves notime consuming mechanical moving mechanisms prior to the firing of acorrective pulse and requires only a single explosive charge to producethe pulse whereby the trajectory of the projectile is corrected. Ashereinafter explained, this pulse is produced in response to radiationfrom the target and always functions to redirect the projectile to thetarget, this result being achieved by means of a nozzle through whichthe gas of the explosive charge is discharged and a mask having anopening so located with respect to this nozzle and t the longitudinalaxis of the projectile that the charge is fired only when said axis isat a predetermined angle with the line of sight between the projectileand target and the target is 180 from this line.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope is indicated by the appended claims.

Referring to the drawings:

FIG. 1 is a sectional view indicating the relation between the variousparts of the explosive system or projectile,

FIG. 2 is an explanatory diagram relating to its operation, and

FIG. 3 indicates the path of the target image on a mask or reticlelocated at the light sensitive detector of the projectile.

The projectile includes a head 10, an adapter 11 and a boom 12 which hasfins 13 at its breech end, is hollow and perforated, and encloses anignition powder 14 arranged to be fired by a primer 15. Surroundingthese parts is a frangible propellant casing, or the like, 16. This partof the projectile is conventional.

The head encloses a shaped charge 17 which is arranged to be fired by afuze 18. This fuze is connected through an electrical lead 19 to apiezoelectric fuze 20, or the like, which functions upon impact of theprojectile to apply to the fuze 18 a voltage whereby it is caused tofire the shaped charge 17 in a well known manner.

The fuze 20 has a reflecting surface 20' and is mounted in a transparentnose or cover 21 which has at its base a curved mirror 22. The mirror 22has a perforation concentric with the longitudinal axis of theprojectile. Alined with this perforation are a lens 23 and a detector orphotocell 24 which is connected through a timed amplifier 25 and a lead26 to a fuze 27. The fuze 27 functions to provide, between its ignitionposition and the firing of a primer 28, a time delay commonly known as asafety arming device prevents firing of a charge at short range orduring launching of the projectile.

Firing of the charge 29 generates a gas which is discharged through anozzle 30 and produces at the gravitational center of the projectile athrust which changes the trajectory of the projectile. This thrust isproduced only whenthe trajectory of the projectile is off the target andis applied only in a direction to redirect the projectileto the target.The medium through which this result is achieved is a spot of light orother radiation reflected from or emitted by the target.

The target, such as a tank, may be illuminated from any convenientpoint. The radiation or light reflected or emitted from it passesthrough the transparent cap 21 to the mirror 22 from which it isreflected to the mirror 20'. Light from the mirror 29" is reflectedthrough the lens 23 which forms an image of the target on a mask 31.

The mask 31 (see FIG. 3) has an aperture 32 which is located from thenozzle 30, the central axis of the nozzle being along the arrow 33 whichindicates the direction of gas discharge.

As the projectile rotates the target image 35 moves about on the mask 31and as it approaches the target this image increases in size. So long asthe image travels near enough the center of the mask to clear theaperture 32 nothing happens. When the image is displaced from the centerof the mask far enough to pass over the aperture 32, the fuze 27 isignited the primer 28 is fired and the charge 29 is fired.

The gun utilized to launch the projectile of the present invention maybe a recoilless rifle. Whatever the type of gun used, it is aimed at thetarget in the customary manner.

Assuming the projectile to be at P (see FIG. 2) and to be moving along aline P-I, whose intersection with the target plane at I, impact point,is displaced from the target T, by a miss distance A, the aperture 32 ofthe mask 31 is displaced at the threshold line of sight error angle Efrom the line PI along which the projectile is moving. The image of thetarget will subtend a lesser angle E which will not pass thru theaperture. When the projectile reaches the point Q, however, the anglesubtended by the image is E and the detector can see the target imagethrough the aperture 32 and the charge 29 is fired, diverting theprojectile through a correction angle equal to E and onto trajectory QT.If the target is located at T the detector 24 sees it at the point R andthe projectile is diverted to the trajectory RT Thus the farther theprojectile impact is displaced from the line of sight between theprojectile and target, the farther away from the target is thetrajectory corrected. Maximum values, fixed by probable miss distancesare determined by operational analysis of the weapon system.

As the above line of sight system geometrically excludes all fallaciousimages optically, the detector mask and amplifier may be electricallytuned to exclude specious targets electrically by responding only to thecharacteristic or signature radiation of the probable target or thespecifically designed reflected radiation projected by an illuminatorfrom the gun site or displaced vantage point.

I claim:

1. A gun fired, fin stabilized projectile having rotation, saidprojectile having a casing with a nose cross sectional area a majorportion of which is transparent to radiations 3 from a target, anexplosive charge carried by said projectile, a nozzle having its axisthrough the gravitational center of said projectile and adapted uponfiring said charge to produce a thrust transversely of the longitudinalaxis of said projectile, electronic means operable to fire said chargein response to radiations from a target received through saidtransparent nose area, said electronic means including a detector oftarget radiations operable to fire said charge in response to suchreceived radiations, means including a mask located in front of saiddetector, rotatable with said projectile and provided with an apertureradially displaced from said longitudinal axis but substantiallyopposite said nozzle, said aperture being located far enough from saidlongitudinal axis to admit target radiations to said detector when saidlongitudinal References Cited in the'file of this patent UNITED STATESPATENTS 2,415,348 Haigney Feb. 4, 1947 2,623,465 Vasse Dec. 30, 19522,822,755 Edwards et al Feb. 11, 1958 2,892,411 Brown et a1. June 30,1959 2,963,973 Estey Dec. 13, 1960

1. A GUN FIRED, FIN STABILIZED PROJECTILE HAVING ROTATION, SAIDPROJECTILE HAVING A CASING WITH A NOSE CROSS SECTIONAL AREA A MAJORPORTION OF WHICH IS TRANSPARENT TO RADIATIONS FROM A TARGET, ANEXPLOSIVE CHARGE CARRIED BY SAID PROJECTILE, A NOZZLE HAVING ITS AXISTHROUGH THE GRAVITATIONAL CENTER OF SAID PROJECTILE AND ADAPTED UPONFIRING SAID CHARGE TO PRODUCE A THRUST TRANSVERSELY OF THE LONGITUDINALAXIS OF SAID PROJECTILE, ELECTRONIC MEANS OPERABLE TO FIRE SAID CHARGEIN RESPONSE TO RADIATIONS FROM A TARGET RECEIVED THROUGH SAIDTRANSPARENT NOSE AREA, SAID ELECTRONIC MEANS INCLUDING A DETECTOR OFTARGET RADIATIONS OPERABLE TO FIRE SAID CHARGE IN RESPONSE TO SUCHRECEIVED RADIATIONS, MEANS INCLUDING A MASK LOCATED IN FRONT OF SAIDDETECTOR, ROTATABLE WITH SAID PROJECTILE AND PROVIDED WITH AN APERTURERADIALLY DISPLACED FROM SAID LONGITUDINAL AXIS BUT SUBSTANTIALLYOPPOSITE SAID NOZZLE, SAID APERTURE BEING LOCATED FAR ENOUGH FROM SAIDLONGITUDINAL AXIS TO ADMIT TARGET RADIATIONS TO SAID DETECTOR WHEN SAIDLONGITUDINAL AXIS IS AT A DEFINITE ANGLE WITH THE LINE OF SIGHT FROMSAID PROJECTILE TO SAID TARGET.